Roscoe Karns (above) played the title role in the popular DuMont Television Network series from 1950 to 1954, one of the longest-running programs on the network. His son, character actor Todd Karns, also appeared in the series. It was a live crime series set in New York City. The DuMont offices and corridors were used as sets since the program was produced on a small budget. .

At the end of each program, Rocky King would exchange telephone small talk with his unseen wife Mabel and, after hanging up, say to no one in particular, "Great girl, that Mabel".

Although most episodes were destroyed, some still exist, including 37 at the UCLA Film and Television Archive. Four episodes of the series were released to DVD on November 21, 2006.